Lecture Notes: Breath Sounds and Their Characteristics

Overview

Breath sounds consist of two phases: inspiration and expiration.
These phases form the respiratory cycle and are essential for describing lung sounds.

Normal Breath Sounds: Termed 'vesicular', these are gentle and rustling.
- Sound resembles "WOOOOOSH-AHHH."
Formation:
- Laminar airflow: uniform, produces no sound.
- Turbulent airflow: chaotic, produces vibrations audible through stethoscope.
Pathway:
- Air enters the upper airway, through larynx and trachea.
- Inspiratory sounds: Generated by turbulent airflow in the lobar and segmental bronchi.
- Expiratory sounds: Produced by turbulent airflow in the larger bronchi and trachea.
Characteristics:
- No gap between inspiration and expiration; continuous sound.
- Inspiration: High-pitched, loud.
- Expiration: Lower-pitched, quieter, shorter.
Auscultation:
- Right lung: three lobes; left lung: two lobes.
- No precise anatomical landmarks; listen to full cycle symmetrically.
- Anterior thorax: Upper and middle lobes sounds.
- Posterior thorax: Predominantly lower lobes.
Summary:
- Soft, low-pitched, rustling.
- Inspiratory longer, louder, higher-pitched.
- Expires from turbulent airflow in central airways.

Description: Resemble "Darth Vader" breathing.
- Sound likened to "Koohhhh Purrrrrr."
Mechanism: Same as vesicular sounds.
- Inspiratory phase: Turbulent airflow in bronchi.
- Expiratory phase: Central airways.
Characteristics:
- Loud, hollow, harsh blowing.
- Pause between inspiration and expiration.
- Expiration: Longer, higher-pitched.
Auscultation:
- Normally over central airways, trachea in the neck.
- Sternal edge, 2nd intercostal space.
- Posteriorly: Levels C7 to T3.
- Abnormal in peripheral chest, indicating underlying pathologies.
Associated Conditions:
- Consolidation (e.g., pneumonia).
- Dense lung fibrosis.
- Lung abscess.
- Collapsed lung adjacent to pleural effusion.